A defendant is charged with beating a victim to death with a set of brass knuckles during the course of a fight in a tavern. The victim was found to have a pistol on his person at the time of the fight. During the course of the trial, the defendant took the stand in his own defense and testified that the victim threatened him with a gun and the defendant had hit the victim with the brass knuckles in self-defense. To rebut the defendant's claim, the prosecution wishes to place the bartender on the stand, who will testify that two years prior to the attack on the victim, she had seen the defendant approach a customer in her tavern from behind, put on a pair of brass knuckles, and strike the customer a severe blow on the side of the face with a brass-knuckled fist. The prosecutor, in accordance with local court rules, has apprised the defense attorney of the general tenor of the bartender's proposed testimony. As soon as the bartender is sworn in, the defense attorney raises an objection. How should the court rule on the admissibility of the bartender's testimony?

A Admissible, as substantive evidence that the defendant did not act in self-defense in beating the victim.

B Admissible, to attack the defendant's credibility.

C Inadmissible, because prior bad acts cannot be admitted to prove the defendant's propensity to commit the specific crime with which he is charged.

D Inadmissible, because the defendant has not put his character in issue in this case.